#include <cstdio>
#define maxn 500001

using namespace std;
long long int v[maxn],a,b,mx;
int i,n,m,k,op;

struct nod
{
    long long int maxim;
    int xleft,xright;
    nod *left,*right;
}*RAD,*r;

nod* creare(int st, int dr)
{
    if(st==dr)
    {
        nod *p = new nod;
        p->xleft = st;
        p->xright = dr;
        p->maxim = v[st];
        p->left = NULL;
        p->right = NULL;
        return p;
    }
    else
    {
        int m=(st+dr)/2;
        nod *p = new nod;
        p->xleft = st;
        p->xright = dr;
        p->left = creare(st,m);
        p->right = creare(m+1,dr);
        p->maxim = p->left->maxim > p->right->maxim ? p->left->maxim : p->right->maxim;
        return p;
    }
}

void afisare(nod *p)
{
    if(a<=p->xleft && p->xright<=b)
    {
        if(p->maxim>mx)
            mx=p->maxim;
        return;
    }
    if(a<=p->left->xright && p->left->xright<=b || a<=p->left->xleft && p->left->xleft<=b)
        afisare(p->left);
    if(a<=p->right->xleft && p->right->xleft<=b || a<=p->right->xright && p->right->xright<=b)
        afisare(p->right);
}

void modif(int poz, int x, nod *p)
{
    if(p->xleft==p->xright)
    {
        p->maxim=x;
        return;
    }
    if(poz <= p->left->xright)
    {
        modif(poz,x,p->left);
        p->maxim = p->left->maxim > p->right->maxim ? p->left->maxim : p->right->maxim;
    }
    else
    {
        modif(poz,x,p->right);
        p->maxim = p->left->maxim > p->right->maxim ? p->left->maxim : p->right->maxim;
    }
}

int main()
{
    freopen("arbint.in", "r", stdin);
    freopen("arbint.out", "w", stdout);
    scanf("%d %d ", &n, &m);
    for(i=1;i<=n;i++)
        scanf("%d ", &v[i]);
    RAD = creare(1,n);

    for(i=1;i<=m;i++)
    {
        scanf("%d %d %d ", &op, &a, &b);
        if(op)
            modif(a,b,RAD);
        else
        {
            mx=0;
            afisare(RAD);
            printf("%d\n", mx);
        }
    }
}